1.3 What is a friend?
In 1992 Robin Dunbar, an anthropologist, suggested that the optimum number of friendships one person can maintain is 148 (Dunbar, 2012). This theory has become known as ‘Dunbar’s number’. Over the last two decades Dunbar has continued to review his theory. While he still maintains that 148 is the optimal friendship network, he talks about the existence of smaller networks within this, each differing in intimacy.
The French philosopher André Comte-Sponville has argued against Dunbar’s basic premise. He believes friendship numbers are much smaller, with true friendship requiring more time, sincerity and intimacy than it’s possible to devote to as many as 148 individuals.
Digital social networks remove many of the physical and time barriers to staying connected with friends face-to-face. So do we need to revise Dunbar’s number in this new digital world of friendships?
Clearly, what you believe depends on how you define ‘friend’. Social networks allow children to connect to hundreds of ‘friends’, but are these friendships the same as face-to-face friendships? Are online friendships a reflection, an extension or something totally different to face-to-face relationships?
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Transcript
Robin Dunbar
Thank you very much. I'm here to convince the five of you in the audience who aren't actually on Facebook that the whole thing is completely overrated and all your prejudices were correct.
Oh my goodness. There are lots of us not on Facebook. I don't know what the rest of you are going to do for the next 14 minutes, but … I guess at some level, and this has happened before with email I think back in the late 80s, early 90s, but particularly when Facebook came on stream, I think there was a promissory note on the tin can from the techies that created it that said, this is going to open you up to the global village, you're going to have hundreds of thousands of friends, all over the world. The real question is, is that so? The short answer is no.
Despite the fact that Facebook allows you to put 5,000 friends up on the can, as it were, in fact, most people don't. As a result of this discussion about who your friends are on Facebook, Facebook actually started to look at their own data. When they did an analysis of the entire, whatever it is, 400 million Facebook users, and looked at all the numbers of friends people had, the average was actually about 150. The modal value, the most common value, is somewhere around 120 or 130, which I think is about right because you have to leave a little room before the 150 for granny, who's not really online yet, and a few odd people like that.
The key to the issue is really that even though you sign up, and can sign up lots and lots of people, in fact you spend most of your time talking to only a very few of them. These are Facebook's own data here. They're looking at the number of people just measured in different ways, that you have, you know, traffic with that you're talking to. And it’s sort of divided up between those who have 50 friends, 150 friends and 500 friends, and although the number of friends listed is increasing by an order of magnitude, by a factor of 10, the number of close friends, if you like, that most of your social time on Facebook is spent talking to, is actually quite small.
It’s only somewhere between 3 and about 10 or so. The reason for that is there appears to be a cognitive limit on the number of individuals that we can keep in a sort of relationship with us. This comes off the back of work we were doing on the size of social groups in monkeys and apes. These are the key data here. This is average group size in different species of monkeys, in different species of apes, chimpanzees, gorillas, gibbons, as it happens. Against a measure of brain size, and you can see particularly for the apes this is a very clear line. This block here turns out to be three separate grades, rather tightly defined grades, a bit like this.
The key thing is, if you plug humans into this regression equation, and the human brain data are from the same data set as all the primate data, we get a predicted value of the great ape equation of about 150. That's what's now known as Dunbar's Number. Ironically, it was so christened, on Facebook.
If you were the person who did that, and you're here today, thank you, very much, for making my career.
Is this really true, that that's the size of a group? The answer is yes. Here's a bunch of casual examples of human organisations that have that sort of size, somewhere between 100 and 200. These are our attempts, really to look at real human relationships, if you like, in this context. These are the sense of sizes for hunter-gatherer groups. All human societies are multi-layered, so these are a series of grouping layers and community layers. It's this one, here, the red dots, which are the key. They're all the same type of cluster of community, and they cluster very nicely around the value of 150 which is the blue lines. The red dotted lines are the confidence intervals around that.
They all fit quite nicely within it. This was our very first attempt to look at what it meant for you as an individual. We asked people to tell us who they were sending Christmas cards to; not the number of cards they were sending but who was in the household – the total number of people in the household. That turns out to be very close to 150. The average in this status set was 154. There's a lot of variability around that. Some of us are incredibly mean and don't send any cards at all. Some people send them to their butcher and their baker and their lawyer and all those important people. But the key is it's nicely peaked here around the 150.
It turns out that the reason for that is it's a problem with your brain. We've been able to show with neuroimaging studies, and a series of neuroimaging studies, and these are now being replicated by other people, so the affect really is quite robust, is that the number of friends you have is essentially a function of the size of this bit of the brain up here right above the eyes. That's the bit that's hugely important in managing social interactions, it turns out. The other bits that are critical along the temporal lobe behind the ear, or, inside the skull by the ear.
It's the circuitry between these two that makes up this social cognition circuit that in turn determines the number of friends you have. What this allows you to do is to understand how other people are thinking, the state of their minds, as it were. It's the number of individuals whose minds you can handle in this kind of way that seems to set the limit on the total number of friends you have. So I'm sorry to have to tell you … well, there is an interesting question as to whether that bit of the brain, or any bit of the brain, can expand or contract as a result of practice during childhood in particular. That's quite likely. I mean the brain is much more plastic than we thought.
I'm really sorry to have to tell most of you here that if you're now in your early 20s, it's too late to change. You're stuck with the friends that you've got.
Why is time important, in the context of friendships?
If you like to think of how you organise your social life, there are two key components. There's that cognitive component that's trying to keep track of the nature of your relationships with other individuals, but time plays a very important component in that process, because it's investing time in your relationships that makes them a relationship. The strength of that relationship, the sense of emotional closeness, is determined by how much time you invest in your individual friendships. Just to illustrate how important this is, your social world really consists of a series of circles which scale very tightly with each other. So, these circles are the number of friends you have, 5, 15, 50 and out to the 150.
As you come in, you're getting obviously a smaller number of friends, but the quality of that relationship is much more intense. That inner circle of five best friends you have, actually account for something in the order of about half of your total social time. About three-quarters of your total social time is devoted to those inner two layers, the 5 and 15 layers, as it were. They're the ones that are really important to you. They provide you with emotional support and so on.
If you don't invest time in those relationships, the quality of those relationships will decay, and here's a rather nice example. We were looking at how many people, the size of that inner circle of five. We got a whole bunch of people to tell us this is not defined in terms of the number, it's defined in terms of the people you feel you would go to in moments of deep emotional or financial crisis, the ones who would really help you out, as it were. People consistently come up with about five as the average. There is a lot of variation around that, but five is the average. We also asked people are you in an active romantic relationship at the moment. Some of them said no and some of them said yes.
The people who said yes only had four close friends in that category.
So the second bad news of today is 'romance is expensive' and it's not just the diamond rings, it's time. All your time is committed, and that relationship is so time consuming, you can't afford to spend time with other people. If you think about what this implies is, forming a romantic relationship costs you a friendship. That person who should have been in here, the fifth person, has now bumped down into the next layer. And believe me, and that means you won't see them so often. If you don't see your friends so often, they ain't going to be your friends. They're very unforgiving.
Just to illustrate this affect, this is what happens when you need to keep the strength of relationships up. These are data on the change in emotional closeness to all your friends (as opposed to family), over an 18 month period as a function of whether you spent less time in conversation with them, about the same across that period, or during the course of that time you increased the amount of conversation time. These are split for the blokes and the girls. The blokes are blue and the green are the girls. You'll all notice that if you spend less time talking to them, emotional closeness just plummets away. It happens very quickly; within about 6 months.
Certainly for girls, if girls keep conversation up, and talk to each other a lot, it helps prevent the decay on the relationship. These are people who have moved away from home, so they can't physically go and see them so easily. They have to make a big effort to go, but they can phone them as well. But I draw your attention to the boys. Apparently, talking does not improve boys' relationships.
There's a slightly more subtle point to this. We also asked them, 'well, tell us all the things you've done with these people. Did you go shopping with them, gone to parties, helped them move house, gone on holiday with them', a whole long list. When we did the same analysis, look what happens. It's the reverse. What prevents boys' relationships decaying is doing stuff together. Apparently, doing stuff together for girls has a negative effect on their relationships. This is my pitch for why the telephone, in particular, digital media in general, things like Facebook, especially so, which are highly female dominated relatively speaking, two thirds of time on Facebook is by women, and why women's phonecall conversations last for an hour on average.
It's just perfectly designed, the technology is perfectly designed for the way females network and manage their social relationships. I also would explain to you, this is why boys’ phone calls only last 7.3 seconds on average.
And that's because, all they have to do is say ‘I'll see you down the pub at seven’.
So how good is the digital world? We did a study last year which looked at how satisfied you felt with the interactions you had with your five closest friends, through different media. This is sort of real life every day stuff. It wasn't constructed in a lab, as it were. Face to face, by Skype, phone calls, instant messaging, texting, email and social networking sites. You can see that face to face and Skype are way better, and it's because you have a sense of co-presence there. You're in the same room together as you are in a face to face interaction. Also, what's important, for sure, is the immediacy of the response you get.
You can see the smile breaking on the face as you start to tell a joke. Jokes are notoriously flat, if you send them on email. Things you'd fall about laughing at, in the pub, not just because you've had too much to drink, but on email you just go, 'why did you bother?' This comes out of these data very nicely. If you also ask, as we did, was there laughter in that conversation, whether it was real laughter or virtual laughter in the sense of emoticons, it seems the level of satisfaction after an interaction in which laughter in some form occurred is much, much higher than an interaction with the same person, when laughter doesn't occur.
The reason laughter is so important in this context, and it seems to be one of the key drivers for creating relationship quality, and I think that's why in lonely hearts ads you see GSOH so often, 'good sense of humour', it's really important in servicing our relationships, but here's why. What laughter does is trigger the release of endorphins. Endorphins are the brain’s own pain killers basically. They give you a very slight opiate high. We tried to look at this by giving a bunch of people comedy videos to watch – Michael McIntyre and various stand-up comedians. We compared them with a bunch of people who watched boring videos, mostly golfing instruction. We measured the endorphin production through pain threshold, like this.
If endorphins are produced, pain thresholds will go up, so you'll see an increase in pain threshold. You can stand more pain after laughing. Sure enough, just look at the difference, it's really clear-cut. This one I really like, because we did it live at the Edinburgh Fringe. This was a stand-up comedy routine. The audience watching stand-up comedy. This was audiences watching playlets at the Edinburgh Fringe, and you see the same effect there. Laughter makes the world go round. Thank you very much.
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Think about what friendship means to you. Then, consider what having digital ‘friends’ might mean for children’s social networks and their understanding of ‘a friend’.
You’ll move now beyond social networks to consider how children engage in virtual environments.